In recent years, an audio conference apparatus provided with a speaker and a microphone integrally in order to conduct audio conference (communication conference) becomes widespread. The audio conference apparatus sends a sound collected by a microphone to a connection destination and emits a sound received from the connection destination by the speaker. In the case of conducting conference by plural persons, such an audio conference apparatus is often installed in the center (for example, the center of a conference desk) of conference participants. Therefore, it is desirable to miniaturize such an audio conference apparatus and, for example, as shown in Patent Reference 1, an audio conference apparatus miniaturized by omitting a case for speaker is proposed.
Also, an apparatus in which plural directional microphones are installed so as to be directed to the periphery around the apparatus is provided in consideration that the apparatus is placed in the center of a conference desk.    Patent Reference 1: JP-A-8-204803